Project Summary/Abstract: Funds are requested to purchase a 4-laser FACSAria from Becton-Dickinson, to be placed in the PI's new Flow Cytometry Core in the Translational Immunology Center [TIC], opening in 2007. The TIC is a new thematic research facility underway at Massachusetts General Hospital's [MGH] Charlestown Navy Yard Research Facility. The TIC will translate advances in basic science to clinical practice in solid organ and bone marrow transplantation, inflammatory bowel disease, tumor immunology and infectious, immunodeficiency and autoimmune diseases. If funded, the requested instrument will serve as the cytometric centerpiece of the TIC's research resource. The PI has an established track record in utilizing polychromatic cytometry for research and clinical work and documents that the requested instrument will provide an essential resource to the needs of the TIC. This instrument will initially serve a multidisciplinary group of 15 primary investigators from 5 departments, representing 67 NIH funded grants; it will further benefit the entire research community located in the Charlestown Research Facility, who presently lack appropriate cytometric instrumentation for their NIH funded work. The PI has served the MGH research community since 1985, and his laboratory has been the only one easily available to all investigators at MGH. This laboratory has a highly skilled operator, who along with the PI, collectively represent well over 40 years of well documented experience in flow cytometry. The laboratory has administered and sustained itself on a combination of user fees, grants and departmental backing when necessary. The laboratory has the documented financial support of both the Department of Pathology and MGH administration. Relevance: This application petitions the NIH for funds to purchase high-technology instrumentation essential to study and understand how cells of the immune system can be used to treat malignancies such as leukemia and lymphoma. Advances in medicine based on similar past work today permit curative kidney and bone marrow transplantations as well as treatments for certain autoimmune and infectious disease.